Research On LiBr Absorption Heat Pump Unit Combining Waste-heat And Geothermal Source

LiBr absorption heat pump, which can recover kinds of low grade waste-heat, is oneof the efficient and energy-saving equipments for utilizing low temperature waste-heat. Itproduces a large number of low temperature waste-heat in the process of sinter cooling,but it has a low recycling rate under existing technology. Therefore, adopting LiBrabsorption heat pump to recover sinter sensible heat in depth, the recycling efficiency ofwaste-heat resources will be well improved.By sinter waste-heat system, absorption heat pump unit and buried pipe heatexchanger system combined, we built the laboratory table to study operatingcharacteristics of all operating conditions on the heat pump unit. Results show that, it canpromote heat pump unit performance by improving the hot water and evaporatingtemperature or reducing the condensing temperature; that improving the hot water,chilled water or cooling water flow can also promote the heat pump unit performance.The model of buried pipe heat exchanger system was set up, and its heat transformationwas simulated， we obtain the temperature fields of100-meter single U-tube,85-meterdouble U-tube and30-meter single U-tube respectively. Analysis shows that, simulationvalue is consistent with the experimental result generally, and6m of drilling spacing canmeet the request of heat exchange. Finally, thermodynamic analysis of the heat pumpsystem is conducted. Results show that exergy loss of Generator is46.98MJ·h^-1, whichaccounts for47.52%; exergy loss of Absorber is29.1MJ·h^-1, accounts for29.44%.Studies have shown that LiBr absorption heat pump combining waste-heat andgeothermal source system can get higher exergy efficiency than vapor compressiongeothermal source heat pump system, to follow principle of “temperature counterparts,cascade utilization”. The result has a certain theoretical and experimental basis for thestudy of double heat source LiBr absorption heat pump.